sql多表关联查询语句

Update t1

Set t1 .age = t2.age

From  #temptest1 t1

Join #temptest2 t2

On  t1.id = t2.id

(补充)Sql Server 2008 Merge命令写法：

merge into #temptest1 t1
using( age,id from #temptest2) t2
on t1.id = t2.id
when matched then
update set t1.age = t2.age